Apart from the engines and the external airflow around the fuselage, the air conditioning system of a modern aircraft may be one of the significant noise sources of the airplane in terms of noise input into the interior of the airplane, in other words, for example, into the cockpit and the cabin region. The noise may be generated by the fans of the air conditioning system, and may be transmitted within the pipe system for the air conduit. Subsequently, the noise may be emitted to the cabin by way of the air outlets. In order to reduce this noise component, sound absorption devices can be integrated in the noise path, for example in the pipe system of the air conditioning system. For example, on the outside of a pipe layout an acoustic absorber, e.g. comprising glass wool, is applied; however, for this purpose the wall between the absorber and the flowing air needs to be perforated or of a grid-shaped design. In addition, on the outside of the absorber an airtight layer is provided. In order to prevent abrasion of the usually very light absorber that is susceptible to being damaged, between the perforated wall and the absorber material a woven material can be inserted that prevents the air flow from taking small particles from the absorber material and the air carrying them along. In DE 10 2006 050 869 a sound absorption device for an air pipe is described in which within a curved pipe section an acoustic element is arranged. However, it has been shown that such measures require a large design space and, furthermore, are associated with additional weight when correspondingly high sound damping is to be achieved, which in turn is demanded by the increasing standards of amenity values for the stay in cabin spaces of airplanes.
There may thus be a need for providing an air conditioning conduit for use in an aircraft, which air conditioning conduit is optimized in terms of the required design space and weight, wherein at the same time the best-possible sound-damping characteristics are to be achieved. In addition, other objects, desirable features and characteristics will become apparent from the subsequent summary and detailed description, and the appended claims, taken in conjunction with the accompanying drawings and this background.